This package includes backported versions of types that were added
to transformers in transformers 0.3, 0.4, and 0.5 for users who need strict
transformers 0.2 or 0.3 compatibility to run on old versions of the
platform, but also need those types.

Those users should be able to just depend on transformers >= 0.2
and transformers-compat >= 0.3.

Note: missing methods are not supplied, but this at least permits the types to be used.

Flags

Use transformers 0.2. This will be selected by cabal picking the appropriate version.

Enabled

Manual

three

Use transformers 0.3. This will be selected by cabal picking the appropriate version.

Disabled

Manual

four

Use transformers 0.4. This will be selected by cabal picking the appropriate version.

Disabled

Manual

five

Use transformers 0.5 up until (but not including) 0.5.3. This will be selected by cabal picking the appropriate version.

Disabled

Manual

mtl

f-mtl Disables support for mtl for transformers 0.2 and 0.3. That is an unsupported configuration, and results in missing instances for ExceptT.

Enabled

Manual

generic-deriving

f-generic-deriving prevents generic-deriving from being built as a dependency.
This disables certain aspects of generics for older versions of GHC. In particular,
Generic(1) instances will not be backported prior to GHC 7.2, and generic operations
over unlifted types will not be backported prior to GHC 8.0. This is an unsupported
configuration.

Enabled

Manual

Use -f <flag> to enable a flag, or -f -<flag> to disable that flag. More info